Natural science is one of the branches of science concerned with the description, understanding and prediction of natural phenomena, based on empirical evidence from observation and experimentation. Mechanisms such as peer review and repeatability of findings are used to try to ensure the validity of scientific advances.
Onion (Allium) cells in different phases of the cell cycle. Growth in an 'organism' is carefully controlled by regulating the cell cycle.
Plato (left) and Aristotle in a 1509 painting by Raphael. Plato rejected inquiry into natural philosophy as against religion, while his student, Aristotle, created a body of work on the natural world that influenced generations of scholars.
Johannes Kepler (1571–1630). Kepler's Astronomia Nova is "the first published account wherein a scientist documents how he has coped with the multitude of imperfect data to forge a theory of surpassing accuracy", therefore laying the groundwork for the scientific method.
Isaac Newton is widely regarded as one of the most influential scientists of all time.
A phenomenon , sometimes spelled phaenomenon, is an observable event. The term came into its modern philosophical usage through Immanuel Kant, who contrasted it with the noumenon, which cannot be directly observed. Kant was heavily influenced by Gottfried Wilhelm Leibniz in this part of his philosophy, in which phenomenon and noumenon serve as interrelated technical terms. Far predating this, the ancient Greek Pyrrhonist philosopher Sextus Empiricus also used phenomenon and noumenon as interrelated technical terms.
The combustion of a match is an observable occurrence, or event, and therefore a phenomenon.
A comparison between a candle flame on Earth (left) and in a microgravity environment, such as that found on the International Space Station (right). The same burning phenomenon is observed, but different flame shape and colouring phenomena are also observed.
Cloud chamber phenomena. Scientists use phenomena to refine some hypotheses and sometimes to disprove a theory. See also animated version.
